DSL - Alcatel - Tweaking - 2k

[renderLolita]

mmm... finally after two three days of browsing the forum I've decided to join this fantastic band of experts, not only coz I obviuosly need your help ( :o ), but to say thanks in advance coz U really helped me even when I was a guest here...

Ok then, this is the question:

I've read all about patches, TCP/IP Analyzer and I'm using on my local the TCP Optimizer as well, and seems that I've learned what is the RWIN...

...but I didnt noticed at least a small increase of d/l speed...

Here is the test...

TCP options string = 020405b40103030001010402

MTU = 1500
MTU is fully optimized for broadband.

MSS = 1460
Maximum useful data in each packet = 1460, which is equal to MSS.

Default Receive Window (RWIN) = 30660
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 30660
RWIN is a multiple of MSS
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 1226.4 kbps (153.3 KBytes/s) @ 200ms
Your RcvWindow limits you to: 490.56 kbps (61.32 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 44 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000

And my approximate round trip times (RTT) in milli-seconds:

Average = 302ms

I'm running w2kSP2 on Athlon 800 with 640MB ram, 46GB hd, Hercules Geforce II mx Dual Display Video, modem Alcatel Speed Touch Manta and my ISP specs r 800/160...

Please help me if I made something wrong, thanks, if ya need something else let me know...

Bye rL

[earthmofo]

Everything looks ok. You calculated your RWIN correctly. What are your actual speeds when you do a speed test?

[renderLolita]

Thnks 4 the reply... now I'm getting 27-30KB down...


Storage

27.1 kilobytes per second

at Bandwidth Place...

[earthmofo]

Try changing the RWIN value to 51100, 64240, 128480 or 256960.

Also, do you have Cablenut installed? There are a few settings that could provide better preformance.

[renderLolita]

All installed my friend... thanks again 4 your interest...

I'm gonna try to contact my ISP for further details...

[funky]

Nonono. You will probably not succeed with the low rwin. I am going to assume that you know how to change Rwins, so here it goes:

513920, 547500, 570860, and 586920

Also, AFD tweaks down below in my sig may help.

[bagheera]

My experience is that RWIN much over 256KB don't help much, and that's a lot of data to deal with over a noisy line (eg, a high RWIN can =reduce= performance under such conditions). I'd:

1= make sure I've got the best network card possible
a= 64b 66MHz PCI one best,
b= 32b 66MHz PCI one 2nd best
c= 32b 33MHz PCI one 3rd best
Stay away from 16b cards. Get one that has the biggest HW buffer possible, preferably one that is dual ported. I've had good luck wth the 3Com server class NIC's.

2= make RWIN 64240, turn off scaling, and test.
3= make RWIN 128480, tweak scaling ;-), and test.
4= keep bumping RWIN until you no longer see a performance improvement, then back off to the last number that did show an improvement.

If you're a "die hard" and running Win98/Me:
5= note the best settings and resultant performance from the procedure above
6= change RWIN back to 64240, turn off scaling, and make the System.ini tweak mentioned on this site. Try an initial size equal to the buffer size of your NIC, and test.
7= bump the RAM reserved in 6 above in multiples of buffer size until you see no performance improvement, then back off to the last number that did show an improvement.
8= Now repeat the RWIN tuning process.
(I'm still trying to find out if there's an equivalent tweak for Win2K, if anyone knows how to reserve a specific area of RAM for the NIC under Win2K/XP, I'd love to hear it)

When you done with all of the above, you will have enough data points to tell you what the best settings are for your machine over that network connection. Good Luck ;-)

[Lobo]

Use SG's System ini tweak set at 7168, type sysedit in run box, Close out of all boxes except System Ini, put it in 386th Enh, thats where it goes , see if it helps you or not, if you don't have alot of RAM it might not.
:) :)

[bagheera]

lobo:
Was your advice for Win 2K/XP or 95/98/Me? I thought System.ini had no effect on 2K/XP systems?

Regarding the use of 7168 as a value, my experience has been that the value should be a mulitple of the NIC buffer size.

(Oh, and I've got 1.5GB of RAM in the "small" Win 2K AS box, so I'm not too worried about that ;-)

[Lobo]

Please read XP tweaks at top of page:)